An anchor nut is a specialized fastening nut used in construction to secure tie rods, bolts, or threaded connections in formwork and shuttering systems. It is usually made of mild steel or high-strength steel and is designed to fit tightly on threaded rods or bolts, providing a firm hold. In shuttering, anchor nuts are commonly used with tie rods to hold opposite formwork panels together and resist the lateral pressure of fresh concrete. They ensure that the panels remain aligned and stable, preventing bulging or shifting during concreting. After the concrete has set, anchor nuts can often be removed and reused for subsequent formwork assemblies.